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kernel-wide: fix missing validations on __get/__put/__copy_to/__copy_from_user()

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I found the following pattern that leads in to interesting findings:

  grep -r "ret.*|=.*__put_user" *
  grep -r "ret.*|=.*__get_user" *
  grep -r "ret.*|=.*__copy" *

The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat,
since those appear in compat code, we could probably expect the kernel
addresses not to be reachable in the lower 32-bit range, so I think they
might not be exploitable.

For the "__get_user" cases, I don't think those are exploitable: the worse
that can happen is that the kernel will copy kernel memory into in-kernel
buffers, and will fail immediately afterward.

The alpha csum_partial_copy_from_user() seems to be missing the
access_ok() check entirely.  The fix is inspired from x86.  This could
lead to information leak on alpha.  I also noticed that many architectures
map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I
wonder if the latter is performing the access checks on every
architectures.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mathieu Desnoyers
2013-09-11 14:23:18 -07:00
committed by Linus Torvalds
parent 20d0e57017
commit 3ddc5b46a8
5 changed files with 39 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

50
net/socket.c
View File

@@ -3072,12 +3072,12 @@ static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
uifmap32 = &uifr32->ifr_ifru.ifru_map;
err = copy_from_user(&ifr, uifr32, sizeof(ifr.ifr_name));
err |= __get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
err |= __get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
err |= __get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
err |= __get_user(ifr.ifr_map.irq, &uifmap32->irq);
err |= __get_user(ifr.ifr_map.dma, &uifmap32->dma);
err |= __get_user(ifr.ifr_map.port, &uifmap32->port);
err |= get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
err |= get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
err |= get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
err |= get_user(ifr.ifr_map.irq, &uifmap32->irq);
err |= get_user(ifr.ifr_map.dma, &uifmap32->dma);
err |= get_user(ifr.ifr_map.port, &uifmap32->port);
if (err)
return -EFAULT;
@@ -3088,12 +3088,12 @@ static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
if (cmd == SIOCGIFMAP && !err) {
err = copy_to_user(uifr32, &ifr, sizeof(ifr.ifr_name));
err |= __put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
err |= __put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
err |= __put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
err |= __put_user(ifr.ifr_map.irq, &uifmap32->irq);
err |= __put_user(ifr.ifr_map.dma, &uifmap32->dma);
err |= __put_user(ifr.ifr_map.port, &uifmap32->port);
err |= put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
err |= put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
err |= put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
err |= put_user(ifr.ifr_map.irq, &uifmap32->irq);
err |= put_user(ifr.ifr_map.dma, &uifmap32->dma);
err |= put_user(ifr.ifr_map.port, &uifmap32->port);
if (err)
err = -EFAULT;
}
@@ -3167,25 +3167,25 @@ static int routing_ioctl(struct net *net, struct socket *sock,
struct in6_rtmsg32 __user *ur6 = argp;
ret = copy_from_user(&r6.rtmsg_dst, &(ur6->rtmsg_dst),
3 * sizeof(struct in6_addr));
ret |= __get_user(r6.rtmsg_type, &(ur6->rtmsg_type));
ret |= __get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len));
ret |= __get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len));
ret |= __get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric));
ret |= __get_user(r6.rtmsg_info, &(ur6->rtmsg_info));
ret |= __get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags));
ret |= __get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex));
ret |= get_user(r6.rtmsg_type, &(ur6->rtmsg_type));
ret |= get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len));
ret |= get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len));
ret |= get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric));
ret |= get_user(r6.rtmsg_info, &(ur6->rtmsg_info));
ret |= get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags));
ret |= get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex));
r = (void *) &r6;
} else { /* ipv4 */
struct rtentry32 __user *ur4 = argp;
ret = copy_from_user(&r4.rt_dst, &(ur4->rt_dst),
3 * sizeof(struct sockaddr));
ret |= __get_user(r4.rt_flags, &(ur4->rt_flags));
ret |= __get_user(r4.rt_metric, &(ur4->rt_metric));
ret |= __get_user(r4.rt_mtu, &(ur4->rt_mtu));
ret |= __get_user(r4.rt_window, &(ur4->rt_window));
ret |= __get_user(r4.rt_irtt, &(ur4->rt_irtt));
ret |= __get_user(rtdev, &(ur4->rt_dev));
ret |= get_user(r4.rt_flags, &(ur4->rt_flags));
ret |= get_user(r4.rt_metric, &(ur4->rt_metric));
ret |= get_user(r4.rt_mtu, &(ur4->rt_mtu));
ret |= get_user(r4.rt_window, &(ur4->rt_window));
ret |= get_user(r4.rt_irtt, &(ur4->rt_irtt));
ret |= get_user(rtdev, &(ur4->rt_dev));
if (rtdev) {
ret |= copy_from_user(devname, compat_ptr(rtdev), 15);
r4.rt_dev = (char __user __force *)devname;